In a liquid crystal display device or a video display device such as an organic electro luminescence (hereinafter referred to as EL) display device, when moisture intrudes into a display panel, characteristics of a liquid crystal layer and an organic EL layer are deteriorated or corrosion occurs in wiring layers and the like. Therefore, the display device includes a structure in which the periphery of the display panel is bonded and sealed by a seal material or the like. Various proposals have been made concerning such a sealing structure for the display panel (JP-A-2005-78946 and JP-A-1-239528).
For example, JP-A-2005-78946 and JP-A-1-239528 propose a method of sealing, with the seal material, the periphery of a display panel including a structure in which electrodes, a light emitting layer, and the like are laminated on a substrate on which thin film transistors (TFTs) for driving peripheral circuits and pixels are provided.